Carboxyl separator of additive self-assembly layer of lithium-sulfur battery and preparation method of carboxyl separator

Abstract

The invention relates to a carboxyl separator of an additive self-assembly layer of a lithium-sulfur battery. In the separator, a conventional battery separator is used as a substrate material by carboxylation, at least one blocking layer formed from the self-assembly layer is introduced to a surface of the substrate material, the self-assembly layer comprises constituents of sodium polystyrene sulfonate, polarized polyvinylidene fluoride or sodium carboxymethyl cellulose, carboxyl on the self-assembly layer and the separator has dual blocking effects on a polysulfide lithium intermediate bodyformed during the charge-discharge process of a sulfur positive electrode, and the stability of the separator can be further ensured by the self-assembly layer. Active substance sulfur in electrochemical reaction can be limited at one side of the positive electrode by the carboxyl separator of the additive self-assembly layer, the polysulfide lithium intermediate body formed during the circulation process of the sulfur positive electrode is prevented from being dissolved in an electrolyte to generate irreversible capacity attenuation, and the cycle property of the sulfur positive electrode isimproved. The invention also comprises a preparation method of the carboxyl separator of the additive self-assembly layer.

Description

technical field [0001] The invention belongs to the field of electrochemical power sources, and in particular relates to a carboxylated separator for an additional self-assembly layer of a lithium-sulfur battery and a preparation method thereof. Background technique [0002] With the rapid development of microelectronics technology, it has greatly accelerated the pace of upgrading in the mobile communication and computer industries. Electrical components are required to be smaller in size, more complete in function, and longer in standby time. In the structure of lithium batteries, the separator is one of the key inner components. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle and safety performance of the battery. A separator with excellent performance plays an important role in improving the overall performance of the battery. The main function of the diaphragm is to s...

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Problems solved by technology

However, this method requires pre-preparation of microporous supports, mesoporous supports and macroporous supports that meet the requirements, including the process of high-temperature pyrolysis of sugar compounds to prepare porous carbon, preparation of slurry and coating. The preparation process has many steps, which is not conducive to the industry. chemical production

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